Open-cathode proton exchange membrane (PEM) fuel cells have a simple construction and minimal balance of plant. Such fuel cells operate in ambient air and are thus less costly and complex and consume less parasitic power than close-cathode fuel cells, which require the provision of oxidant flow channels and external oxidant supply systems.
However, in high power operations, heat management of open-cathode PEM fuel cells is an issue, particularly for compact fuel cell stacks, as large quantities of heat are generated in small and limited spaces.
Efficient and even cooling is required for stable operation of fuel cells. Accumulated heat dries up proton conductive membranes and results in high ohmic losses and a deteriorated power output. Uneven thermal distribution irreversibly damages the membranes and compromises the durability of the fuel cells.
It is therefore desirable to have a fuel cell assembly that can be cooled effectively and that operates with a substantially uniform thermal distribution.